PT  - JOURNAL ARTICLE
AU  - Walter W. Hauck
AU  - Robert C. Capen
AU  - Janice D. Callahan
AU  - James E. De Muth
AU  - Henry Hsu
AU  - David Lansky
AU  - Nancy C. Sajjadi
AU  - Sally S. Seaver
AU  - Robert R. Singer
AU  - Doris Weisman
TI  - Assessing Parallelism Prior to Determining Relative Potency
DP  - 2005 Mar 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - 127--137
VI  - 59
IP  - 2
4099  - http://journal.pda.org/content/59/2/127.short
4100  - http://journal.pda.org/content/59/2/127.full
SO  - PDA J Pharm Sci Technol2005 Mar 01; 59
AB  - In the course of preparing a revision to Chapter 〈111〉 of the US Pharmacopeia, the revision committee came to a unanimous agreement that the method for assessing parallelism that is currently presented in 〈111〉 and in the European Pharmacopeia's Chapter 5.3 is flawed and should be replaced. The symptoms are that perfectly acceptable assay results may fail due to good precision and that obviously faulty assay results may pass due to poor precision. The flaw is that the wrong statistical technique has been used. We propose an alternative approach based on the equivalence testing paradigm that does not have these shortcomings. Equivalence testing requires the establishment of equivalence limits. Specific approaches for establishing equivalence limits are discussed.